Characteristics of Optic Disc and Peripapillary Structures in Myopia Based on Swept-Source Optical Coherence...

To compare optic disc morphology and peripapillary structures in patients with varying degrees of myopia using swept-source optical coherence tomography, and to analyze their correlation with the peripapillary choroidal vascularity index.

Patients aged 18-40 years with myopia were enrolled. Patients were divided into three groups according to spherical equivalent refraction: group A (low myopia, -3.00 D < spherical equivalent ≤ -0.5 D), group B (moderate myopia, -6.00 D < spherical equivalent ≤ -3.00 D), and group C (high myopia, spherical equivalent ≤ -6.00 D). We compared the incidence and area of parapapillary atrophy in the β-zone (β-parapapillary atrophy) and the γ-zone (γ-parapapillary atrophy). The incidence and degree of optic disc tilt and optic disc rotation were also compared. We further examined differences in peripapillary choroidal thickness and peripapillary choroidal vascularity index among the groups. Linear regression analysis evaluated the relationships between peripapillary choroidal vascularity index and these parameters.

In groups with higher myopia, the incidence and area of parapapillary atrophy, as well as optic disc tilt, increased. No significant difference in optic disc rotation was observed among the groups; however, downward optic disc rotation was more common in groups with higher myopia. Temporal peripapillary choroidal thickness was positively correlated with peripapillary choroidal vascularity index. The area of β-parapapillary atrophy showed a negative correlation with temporal, superior, and inferior peripapillary choroidal vascularity index. The area of γ-parapapillary atrophy was negatively correlated with temporal and nasal peripapillary choroidal vascularity index.

The parapapillary atrophy area increases in higher myopia groups. γ-parapapillary atrophy enlarges predominantly in low-to-moderate myopia. Downward optic disc rotation is more prevalent in highly myopic groups. Reduced temporal peripapillary choroidal thickness may indicate impaired peripapillary choroidal blood flow.